def test_sparse_regression():
"""Check regression for various parameter settings on sparse input."""
rng = check_random_state(0)
X_train, X_test, y_train, y_test = train_test_split(boston.data[:50],
boston.target[:50],
random_state=rng)
class CustomSVR(SVR):
"""SVC variant that records the nature of the training set"""
def fit(self, X, y):
super(CustomSVR, self).fit(X, y)
self.data_type_ = type(X)
return self
parameter_sets = [
{"max_samples": 0.5,
"max_features": 2,
"bootstrap": True,
"bootstrap_features": True},
{"max_samples": 1.0,
"max_features": 4,
"bootstrap": True,
"bootstrap_features": True},
{"max_features": 2,
"bootstrap": False,
"bootstrap_features": True},
{"max_samples": 0.5,
"bootstrap": True,
"bootstrap_features": False},
]
for sparse_format in [csc_matrix, csr_matrix]:
X_train_sparse = sparse_format(X_train)
X_test_sparse = sparse_format(X_test)
for params in parameter_sets:
# Trained on sparse format
sparse_classifier = LazyBaggingRegressor(
base_estimator=CustomSVR(),
random_state=1,
**params
).fit(X_train_sparse, y_train)
sparse_results = sparse_classifier.predict(X_test_sparse)
# Trained on dense format
dense_results = LazyBaggingRegressor(
base_estimator=CustomSVR(),
random_state=1,
**params
).fit(X_train, y_train).predict(X_test)
sparse_type = type(X_train_sparse)
types = [i.data_type_ for i in sparse_classifier.estimators_]
assert_array_equal(sparse_results, dense_results)
assert all([t == sparse_type for t in types])
assert_array_equal(sparse_results, dense_results)
def test_single_estimator():
"""Check singleton ensembles."""
rng = check_random_state(0)
X_train, X_test, y_train, y_test = train_test_split(boston.data,
boston.target,
random_state=rng)
clf1 = LazyBaggingRegressor(base_estimator=KNeighborsRegressor(),
n_estimators=1,
bootstrap=False,
bootstrap_features=False,
random_state=rng).fit(X_train, y_train)
clf2 = KNeighborsRegressor().fit(X_train, y_train)
assert_array_equal(clf1.predict(X_test), clf2.predict(X_test))
def test_base_estimator():
"""Check base_estimator and its default values."""
rng = check_random_state(0)
# Classification
X_train, X_test, y_train, y_test = train_test_split(iris.data,
iris.target,
random_state=rng)
ensemble = LazyBaggingClassifier(None,
random_state=0).fit(X_train, y_train)
assert_true(isinstance(ensemble.base_estimator_, DecisionTreeClassifier))
ensemble = LazyBaggingClassifier(DecisionTreeClassifier(),
random_state=0).fit(X_train, y_train)
assert_true(isinstance(ensemble.base_estimator_, DecisionTreeClassifier))
ensemble = LazyBaggingClassifier(Perceptron(),
random_state=0).fit(X_train, y_train)
assert_true(isinstance(ensemble.base_estimator_, Perceptron))
# Regression
X_train, X_test, y_train, y_test = train_test_split(boston.data,
boston.target,
random_state=rng)
ensemble = LazyBaggingRegressor(random_state=0).fit(X_train, y_train)
assert_true(isinstance(ensemble.base_estimator_, DecisionTreeRegressor))
ensemble = LazyBaggingRegressor(DecisionTreeRegressor(),
random_state=0).fit(X_train, y_train)
assert_true(isinstance(ensemble.base_estimator_, DecisionTreeRegressor))
ensemble = LazyBaggingRegressor(SVR(),
random_state=0).fit(X_train, y_train)
assert_true(isinstance(ensemble.base_estimator_, SVR))
def test_bootstrap_samples():
"""Test that bootstraping samples generate non-perfect base estimators."""
rng = check_random_state(0)
X_train, X_test, y_train, y_test = train_test_split(boston.data,
boston.target,
random_state=rng)
base_estimator = DecisionTreeRegressor().fit(X_train, y_train)
# without bootstrap, all trees are perfect on the training set
ensemble = LazyBaggingRegressor(base_estimator=DecisionTreeRegressor(),
max_samples=1.0,
bootstrap=False,
random_state=rng).fit(X_train, y_train)
assert_equal(base_estimator.score(X_train, y_train),
ensemble.score(X_train, y_train))
# with bootstrap, trees are no longer perfect on the training set
ensemble = LazyBaggingRegressor(base_estimator=DecisionTreeRegressor(),
max_samples=1.0,
bootstrap=True,
random_state=rng).fit(X_train, y_train)
assert_greater(base_estimator.score(X_train, y_train),
ensemble.score(X_train, y_train))
def test_reproducibility():
rng = check_random_state(0)
# Classification
X_train, X_test, y_train, y_test = train_test_split(iris.data,
iris.target,
random_state=rng)
ensemble = LazyBaggingClassifier(random_state=rng)
ensemble.fit(X_train, y_train)
assert_array_equal(ensemble.predict(X_test), ensemble.predict(X_test))
# Regression
X_train, X_test, y_train, y_test = train_test_split(boston.data,
boston.target,
random_state=rng)
ensemble = LazyBaggingRegressor(random_state=rng)
ensemble.fit(X_train, y_train)
assert_array_equal(ensemble.predict(X_test), ensemble.predict(X_test))
def test_regression():
"""Check regression for various parameter settings."""
rng = check_random_state(0)
X_train, X_test, y_train, y_test = train_test_split(boston.data[:50],
boston.target[:50],
random_state=rng)
grid = ParameterGrid({"max_samples": [0.5, 1.0],
"max_features": [0.5, 1.0],
"bootstrap": [True, False],
"bootstrap_features": [True, False]})
for base_estimator in [None,
DummyRegressor(),
DecisionTreeRegressor(),
KNeighborsRegressor(),
SVR()]:
for params in grid:
LazyBaggingRegressor(base_estimator=base_estimator,
random_state=rng,
**params).fit(X_train,
y_train).predict(X_test)
def test_multioutput():
X, y = make_multilabel_classification(n_samples=100, n_labels=1,
n_classes=5, random_state=0,
return_indicator=True)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
est = LazyBaggingClassifier(random_state=0, n_estimators=10,
bootstrap=False)
est.fit(X_train, y_train)
assert_almost_equal(est.score(X_train, y_train), 1.)
y_proba = est.predict_proba(X_test)
y_log_proba = est.predict_log_proba(X_test)
for p, log_p in zip(y_proba, y_log_proba):
assert_array_almost_equal(p, np.exp(log_p))
est = LazyBaggingRegressor(random_state=0, n_estimators=10,
bootstrap=False)
est.fit(X_train, y_train)
assert_almost_equal(est.score(X_train, y_train), 1.)